Hyperemia Analysis Software for Assessment of Conjunctival Hyperemia Severity

We developed a hyperemia analysis software, which can quantitatively assess the degree of conjunctival hyperemia, and evaluated the reproducibility and reliability of its percent coverage. In addition, we compared the clinical grading and the percent coverage to examine the applicability of the software analysis.

We took images of the temporal conjunctiva with slit lamp microscopes. We used our hyperemia analysis software to detect blood vessels in the region of interest using its image processing capabilities and obtained a ratio of the area occupied by blood vessels to the rest of the area. In addition, we used the clinical evaluation criteria of the Japanese guidelines for allergic conjunctival diseases 2017 to clinically grade the hyperemia in each eye. Nine evaluators examined the images and graded the severity of hyperemia into four stages. We looked for a statistical correlation between the results of the hyperemia analysis software and the clinical grading.

The percent coverage of the blood vessels in the region of interest calculated by the hyperemia analysis software correlated with the arithmetic average of our clinical grading (r = 0.953; 95% CI, 0.8470340-0.9862136).

The percent coverage from our hyperemia analysis software reflects the clinical grading score, suggesting that our software can be used to obtain a detailed analysis of conjunctival hyperemia.